8. Exercise VIII

1. It is difficult to burn a heap of green leaves but dry leaves catch fire easily. Explain.

 

Since the green leaves contain some oxygenwatercarbon monoxide, the ignition temperature decresesincreases, making it difficult to burn. On the other hand, dry leaves are waterlessoxygenless and quickly catch fire (having highlow ignition temperature).

 

2. Which zone of a flame does a goldsmith use for melting gold and silver and why?

   

To melt gold and silver, a goldsmith uses the luminous outermost zonenon-luminous inner zone non-luminous outermost zone  of a flame, which is the hottest and has the highest temperature.